LAMARCK'S COJYCHOLOGY. 



ANNULATA forms the Ninth Class of Lamarck's Division 



of Animal Nature. 



SEDENTARY ANNULATA 



Composes the third order of the above class. They are usually found 

 attached to marine substances, and inhabit membranous or horny tubes, more 

 or less incrusted with grains of sand or fragments of shells; or are solid, cal- 

 careous and homogeneous; and are divided into four families, viz. — Dorsalia, 

 Maldania, Amphitritea, and Serpulea. 



DORSALIA.— Two Genera. 

 Arenicola. Has no shell. Ency. Meth. pi. XXXIV. fig. 13. 



Siliquaria. Shell tubular, irregularly twisted, tapering towards the pos- 

 terior end, which is sometimes spiral; anterior extremity open; and a longi- 

 tudinal, subarticulated fissure throughout its whole length. Crouch II. of 

 Lam. pi. I. fig. 1. 



S. anguina, S. muricata, S. laevigata, S. lactea. 



MALDANIA.— Two Genera. 



Clymene. Tube slender, open at both ends, the exterior incrusted with 

 sand and pieces of shells.* 



* I have not been able to procure a figure of the Clymene Amphystoma, of which species only the 

 genus is composed. 



